After Colloseum and XD people haven't been too confident that they can trust that a 3D RPG will be good.
Plus, Pokemon Stadium and Pokemon Stadium 2 are without a doubt the best, and the very hardest Pokemon games ever. Most people want a Pokemon Stadium 3 for the Wii, not an RPG and definately not a Colloseum 2. PBR was a step closer back to the Stadium games, so hopefully they'll realize that the Stadium games are the best.
It's just that the whole idea of having a list of all the Pokemon to choose from to mix and match as you wish, as much as you want is awe-inspiring. I'd rather than than the next pair of 5th generation games. Plus, I've had the Stadium games for over half a decade, and I haven't got halfway through yet. I completed Diamond in under a fortnight of casual playing. It's clear which one is harder...